GM Service Manual Online
For 1990-2009 cars only

This information provides repair recommendations and general guidelines for steel classified as Ultra High Strength Steel, also know as UHSS. This type of steel normally has a tensile strength greater than 700 MPa. This includes the common steel names of:

    • Ultra High Strength Steel (UHSS)
    • Martensitic Steel (MS)
    • Press Hardened Steel (PHS)
    • Boron Steel

General Motors recommends the following when repairing or replacing this type of steel during collision repair.

Note: 

   • Repair of this type of steel is not recommended.
   • This type of steel should be replaced only, at factory joints. Sectioning or partial replacement is not recommended.
   • The use of heat to repair damage is not recommended for this type of steel.
   • Stitch welding is not recommended for this type of steel.
   • This type of steel can not be used as a backing reinforcement or a sleeve for a sectioning joint.

Recommended Repairs:

    • Squeeze resistance spot welding can be used to replace factory spot welds, where applicable.
    • MIG plug welding can be used to replace factory spot welds.
    • MIG brazing can be used to replace factory spot welds.